1. Field of the Invention
The present invention relates to a one-way clutch of roller type used as a torque transmitting element or a back stopper in a driving apparatus of a motor vehicle, an industrial machine and the like, for example.
2. Related Background Art
In general, a one-way clutch of roller type is comprised of an outer race, an inner race disposed in concentric with the outer race, a plurality of rollers disposed between an outer peripheral surface of the inner race and an inner peripheral cam surface of the outer race and adapted to transmit torque, and springs contacted with idle rotation sides of the rollers.
With this arrangement, in the one-way clutch, the inner race is designed so as to be rotated only in one direction with respect to the outer race by means of a cam mechanism constituted by the rollers and the cam surfaces. That is to say, the inner race is designed so that it is idly rotated relative to the outer race in one direction, and on the other hand, it applies rotational torque to the outer race through the cam mechanism only in an opposite direction.
Further, to obtain positive engagement, the one-way clutch of roller type must be constructed so that the rollers as torque transmitting members and the springs for biasing the rollers are not dislodged from respective pockets axially and radially.
In particular, in a one-way clutch of roller type of a motor bike, since the number of rollers is small (for example, three or six), if the respective rollers are not engaged positively, a design torque capacity may not be maintained.
Japanese Patent Application Laid-open No. 8-61192 (1996) discloses a one-way clutch of roller type in which a plurality of projections are provided in an opening portion of an outer race so that rollers and springs are prevented from being dislodged when the one-way clutch of roller type is assembled to an engine of an automatic motor bike.
Japanese Patent Application Laid-open No. 2004-346951 discloses a one-way clutch in which accommodating portions for accommodating rollers and compression springs are not required to be formed separately by providing a base plate having recesses for accommodating the rollers and the compression springs together, thereby suppressing a manufacturing cost.
As disclosed in the above-mentioned Japanese Patent Application Laid-open No. 8-61192 (1996) and Japanese Patent Application Laid-open No. 2004-34695, in the one-way clutches used as starters of the motor bikes, there is no adequate countermeasure in which, during a process for assembling the roller clutch with the outer race incorporating the outer race, rollers and springs, the rollers or sprags are prevented from being dislodged and the rollers and the springs are prevented from being dropped during the clutch is assembled to the motor bike. Further, additional side plates and additional drilling operations must be provided, thereby increasing the manufacturing cost.